Abstract: The invention discloses cancer vaccines comprising lipid-nucleic acid formulations in combination with one or more tumor-associated antigens which are capable of stimulating strong, Th-1 biased cellular immune responses to said tumor-associated antigens in vivo. It is further disclosed the subject cancer vaccines provide therapeutic efficacy in treating tumors in an animal.

Abstract: The invention discloses that methylated nucleic acids, particularly methylated oligonucleotides, and more particularly methylated oligonucleotides bearing a methylated cytosine of a CpG dinucleotide motif can be made immunostimulatory in vivo, by encapsulation of the nucleic acid in a lipid particle. It is further disclosed that encapsulated methylated nucleic acids that are ordinarily not immunostimulatory in vivo are as effective or even more effective than their encapsulated unmethylated counterparts. Also disclosed are methods for activating and/or expanding dendritic cell populations in response to antigenic stimulation using the compositions and methods disclosed herein.

Abstract: The invention is based on the discovery that vaccines against pathogens, exemplified herein by hepatitis B, can be formulated to enhance stimulation of Th1 type humoral and cellular immune responses by combining a lipid particle with an encapsulated immunostimulatory oligonucleotide (LNA). The LNA is further associated with an antigen from the pathogen. The vaccines may also use two or more different epitopes from the same antigen, or different antigens from the pathogen. Such vaccines are particularly effective in enhancing a Th1 type humoral response when the antigen is coupled to the lipid nucleic acid particle and when the nucleic acid particle has phosphorothioate (PS) backbone. An enhanced humoral response is demonstrated, for example, by a strong early peak of IFN-gamma production observed within hours of vaccination followed by second stronger peak of IFN-gamma production observed several days later, correlated with antibody isotype switching.